DETERMINING OPTIMAL BALLASTING
A method and system for selecting and indicating to a user one from a plurality of available ballasting options for an agricultural vehicle when coupled to an agricultural implement. The implement type defines operating ranges of discrete values for first, second and optionally third operational parameters of the vehicle, with the differing combinations defining a values subset. An optimal choice from the available ballasting options is made for each combination in the values subset, and a selection from the optimal choices based on prevalence or probability of occurrence is made and presented to the user. Operational parameters may include operating speed, loading due to implement weight and engine power.
The invention is related to tractors and other agricultural vehicles on which may be mounted various combinations of ballasting weights, and in particular to methods for optimising selection from among the various combinations. The invention also relates to a programmable device configured to perform the method in response to input from a user and to a software utility for programming such a device.
Description of Related ArtIt is known to attach ballast in the form of one or more additional weights to the front, rear or the wheels of an agricultural vehicle to counteract external forces mainly applied by implements attached. With agricultural tractors, most heavy implements are attached to the rear, and ballasting weights on wheels and at the front of the vehicle are very common. Rear mounted ballasting weights are used for front-loader operation.
The choice of the right ballast is very complex, as described for example in commonly-assigned International patent application WO2013/013915, due to the fact that several influencing parameters must be considered. If these parameters are known, it is a matter of mechanics to determine the ballast configuration. However, this requires extensive knowledge on the part of the operator which is not present in many cases, especially if untrained persons are concerned. Even a system just automatically requesting the parameters would overload the operator as much parameter data will not be available to them or depends on the operation in the field. Providing a system which receives the parameters without the operators input would require various sensors to determine the parameters and thereby be quite costly.
As an alternative approach, some standalone (offline) ballasting assistance systems calculate ballast weight by assuming average values for these parameters, but this results in vague ballasting recommendations. An example of such an offline ballasting assistance system is the Deere 9030 series spreadsheet currently downloadable from http://www.deere.com/en_US/docs/agriculture/learn_more/tractors_ballast_calculator/9030_s eries_wheel_tractors_ballast_calc.xls
It is an object of the present invention to provide a method for optimising ballast weight selection and a ballasting assistance system for implementing the same which avoids at least some of the above-mentioned disadvantages.
In accordance with the present invention there is provided a method for selecting and indicating to a user one from a plurality of ballasting options for an agricultural vehicle when coupled to an agricultural implement, comprising:
within a first range of discrete values of a first operational parameter of the vehicle and a first range of discrete values of a second operational parameter of the vehicle, using a received identifier for a selected implement to look up a second range, less than or equal to the first range, of discrete values of the first parameter, and a second range, less than or equal to the first range, of discrete values of the second parameter to obtain a values subset from the combinations of discrete first and second operational parameter values;
deriving an optimal selection from the plurality of ballasting options for each combination in the values subset;
identifying one ballasting option selection on the basis of a predetermined selection criteria; and
indicating the identified selection to the user.
By considering ranges of two or more operational parameters, tolerance for those factors such as hardness of ground (which will not generally be known at set up) may be incorporated in the decision as to which of the ballasting options available to a user would be optimal, that is to say most likely to be suited in a variety of conditions. The operational parameters of the vehicle may include direct values such as a working speed and/or an engine loading, as well as indirect or resultant values such as a vertical load due to an implement on a connection between the said implement and the vehicle: whether due to an implement or the vehicle alone, these values will be referred to herein as vehicle operational parameters.
Also in accordance with the present invention there is provided a ballasting assistance system for an agricultural vehicle when coupled with an agricultural implement, the system comprising:
a display device;
a data storage device; and
a data processing device in communication with the display device and the data storage device, the data processing device configured to select one from a plurality of stored ballasting options for the agricultural vehicle when coupled to a selected agricultural implement, by performing the steps of:
within a first range of discrete values of a first operational parameter of the vehicle and a first range of discrete values of a second operational parameter of the vehicle, using a received identifier for the selected implement to look up in the data storage device a second range, less than or equal to the first range, of discrete values of the first parameter, and a second range, less than or equal to the first range, of discrete values of the second parameter to obtain a values subset from the combinations of discrete first and second operational parameter values;
deriving a respective optimal selection from the plurality of ballasting options for each combination in the values subset;
identifying one ballasting option selection on the basis of a predetermined selection criteria; and
displaying the identified one ballasting option selection on the display device.
The display device may be a touch screen device and the received identifier may be obtained from a look-up table in the data storage device in response to user selection via the touch screen from a menu of implement types displayed. Alternately, the system may further comprise wireless communication means, with the received identifier being obtained from a remotely stored look-up table in response to user selection via the data processing device.
In a further aspect of the present invention there is provided a data storage device carrying data defining a software utility, said software utility when loaded to a data processing device in communication with a display device providing a ballasting assistance system for an agricultural vehicle coupled with an agricultural implement in which ballasting assistance system the data processing device is configured to select one from a plurality of stored ballasting options for the agricultural vehicle when coupled to the agricultural implement, by performing the steps of:
within a first range of discrete values of a first operational parameter of the vehicle and a first range of discrete values of a second operational parameter of the vehicle, using a received identifier for the selected implement to look up in the data storage device a second range, less than or equal to the first range, of discrete values of the first parameter, and a second range, less than or equal to the first range, of discrete values of the second parameter to obtain a values subset from the combinations of discrete first and second operational parameter values;
deriving a respective optimal selection from the plurality of ballasting options for each combination in the values subset;
identifying one ballasting option selection on the basis of a predetermined selection criteria; and
displaying the identified one ballasting option selection on the display device.
Further features and advantages are recited in the dependent sub-claims to which reference is now made.
Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:
A ballasting method embodying the present invention can be used in several systems, including:
-
- OFFLINE-Ballasting assistance system (just application software and an associated interface running on a programmable device or on a vehicle such as a tractor without any measurements/input from machinery).
- OFFLINE-Ballasting assistance system in combination with a tyre pressure control system to adapt tyre pressure on the machinery including parameter input (e.g. by wheel load sensors).
- ONLINE Ballasting assistance on a tractor including tyre pressure control.
The system is described initially on the basis of an OFFLINE ballasting assistance.
The figure shows a main menu 16 displayed on the HMI 14 with a first row R.1 of input buttons (or touch sensitive areas) allow the operator to define how the implement is attached to the tractor, with R1.1 indicating a trailed implement, R1.2 indicating semi-mounted, and R1.3 fully mounted. The mode of attachment influences the mechanical balancing about a pivot point (PP;
A second set of interface input buttons R.2 allows the operator to input the type of attached implement, such as a plough (button R2.1), disc harrow (R2.2) or seed drill (R2.3). In contrast to other ballasting assistance systems, the choice of a generic implement type does not set predetermined values to be considered during calculation but instead delivers from memory 12 a range for some of the parameters. This arrangement is simple to understand and use for an unskilled operator. One or more buttons R2.8 may be assigned to specific implements of a user for which the optimal ballasting selection has previously been made and stored. A further optional input area S provides a pair of sliders s1, s2 enabling a more skilled user to input an operating speed range as minimum and maximum values (5-7 km/h in the example) which input values may be set to override any stored values for the speed range in subsequent calculations. Where the stored value takes precedence over user input, the area S may simply be used to provide a visual indicator of a stored speed range to the user.
As an example the vehicle operating parameter values stored for “Plough” (button R2.1) may be:
-
- vertical load (shown as F_Stuetz in
FIG. 2 ): 0-3 tonnes - working speed: 8-12 km/h
- Engine load: >90%
- vertical load (shown as F_Stuetz in
Further parameters beyond load and speed may be stored. For example, since a seed drill is not only dragged over ground but also has hydraulic drives driven during field operation, a Power Split value is also stored, containing the ratio between power used to drag the implement and used to drive hydraulic or pneumatic drives.
As an example the values stored for “Seed Drill” (button R2.3) may be:
-
- vertical load: 1-6 tonnes
- working speed: 12-16 km/h
- Engine load: >90%
- Power split (hydraulic/drag): 40/60
In this arrangement, some of the values for each implement are stored as ranges in order to recognise the fact that for example the vertical load depends on factors including the working depth and ground condition (soft soil, hard soil etc.), both of which will be unknown when using the present ballasting assistance system.
The system also considers parameters which are predetermined by the vehicle manufacturer, namely the geometric relations which influence the force balance are defined by vehicle data, including wheel separation, centre of gravity, and vehicle weight.
RB Rear axle-mounted ballast
SP Centre of gravity (mass and position) for unloaded vehicle
FB Front ballast
x_1 horizontal separation of hitch point and pivot point PP
x_2 horizontal separation of pivot point PP and SP
x_3 horizontal separation of pivot point PP and centre of front axle
x_4 horizontal separation of pivot point PP and FB mounting
z_1 vertical separation of hitch point and pivot point PP
F_Zug drag force
F_Steutz vertical load on hitch point
F_z, HA wheel load on rear axle(s)
F_z, VA wheel load on front axle(s)
Furthermore details of the power flow or other parameters are predetermined depending on vehicle configuration, such as:
-
- Nominal engine performance (say 500 hp/373 kW),
- Overall efficiency between motor and wheel (for calculating F_U, F_Zug)
- Optimal distribution of wheel load (ceta_opt): ceta=F_z, VA/F_z, HA
- Assumed average slippage of the wheel on ground
In addition to this detail about the physical parameters of the unloaded vehicle, the stored data on which the derivation is based also includes available ballast variants. In a new machine scenario, the range of ballast variants may be taken from the manufacturer's price list. Once delivered, the system may be configured to give an operator the choice to add or reduce the list depending on the weight availability (for example to restrict the choice only to those ballast weights that the operator owns or may borrow from neighbours).
The general method for optimal ballast determination by the on-board or ancillary system of the tractor or other agricultural vehicle, is represented by the flow chart of
Returning to
Taking the above example values stored for “Seed Drill” (button R2.3) into the example, at step 106 a first value v within the range of working speeds is taken (e.g. 12 km/h). Next is the start of a loop 107 which is repeated across the range of discrete values of working speed v, for example increments of 1km/h. The first operation in loop 107, at step 108, is to take a first value within the range of discrete values of vertical loads F_Stuetz (e.g. 1 tonne). The following loop 109 is repeated across the range of vertical loads F_Stuetz_min . . . F_Stuetz_max before the next value of speed v is selected prior to the next iteration of loop 109. As will be recognised, the number of loops 107, 109 processed thereby depends on the chosen increment between the discrete values within the ranges of these operational parameters.
At the start of loop 109, at step 110, the sum of the circumferential forces of the wheels (at point PP) F_U is obtained. In an offline mode, this may be derived from engine performance data, engine load (optionally input by an skilled user), and efficiency factor assumptions (assumed from vehicle configuration and working speed or received as skilled user directly input data). In an online mode, F_U may be obtained from sensor monitoring of gearbox fluid pressure and rotation speed.
At step 112, the optimal total wheel load F_Ges,opt is calculated by the formula
F_Ges,opt=F_U/mue_opt
where mue_opt is a factor determined by environmental conditions of the ground being worked and typically ranges from 0.51 (hard) to 0.55 (easy), with 0.53 being a typical intermediate value. Additional user input may include a qualitative estimation of the environmental conditions (weather, terrain, soil), such as “easy”, “normal”, “difficult”: with this information the value of mue_opt can be adjusted.
In the loop indicated generally at 114, for each of the available ballast variants identified in step 100, the first step 116 is calculation of the respective front (F_z, VA) and rear (F_z, HA) wheel axle loads depending on the ballast variant, and based on the operator-identified type of device and implement connection type (which in turn enables look-up of hitch loading F_Stuetz). The additionally required drawbar pull is derived from F_U by assuming an average slippage and rolling resistance.
Next in the loop, at step 118 and taking the axle loadings from step 116, calculation of the differential current to the optimum value is performed according to:
Diff_Ges=(F_z, HA+F_z, VA)−F_Ges, opt
and differential current of the optimum distribution of the wheel load (Diff_Vert), according to:
Diff_Vert=(F_z, VA/F_z, HA)−ceta_opt
where the optimal distribution of wheel load (ceta_opt) is a predetermined parameter. For conventional tractors with a smaller front and larger rear wheel, ceta_opt=0.667 is a common assumption, which is a distribution of 60% load on the rear axle and 40% on the front axle.
At step 120 the differential currents from step 118 in loop 114 are assessed, with the sum for each ballast variant i being:
sum(i)=w_mue*|Diff_Ges|+w_ceta*Diff_Vert
with w_mue and w_ceta being free selectable weighting factors.
Steps 114 -120 are repeated until the each/last ballast variant has been processed providing sum(i) for each ballast variant. In step 122, the optimal ballast variant (jth variant) is determined as being the one whose sum (i) is the smallest compared with all the other ballast variants (wherein the ideal case is zero).
Steps 114-120 are repeated to give an array of optimum ballast selections (from currently available ballast options) based on two or more factors selected from hitch loading weight (vertical load F_Stuetz), working speed v, engine load and hitch type/geometry.
After repeating loops 107 and 109 (with steps 106 and 108) an optimal ballast variant is determined for each value of working speed and vertical load as shown in
The 3D table of
An alternative method to determine the ballast recommendation is shown in
Based on Gaussian distribution (as schematically shown with graphs 140), each of the ballasting variants determined at step 124 is given a probability of occurrence. The ballast variant with the highest overall sum is then selected. In
As mentioned above, the invention may additionally be embodied in an ONLINE ballasting/tyre pressure assistance system. Such a system is additionally provided with means in the form of sensors (8;
-
- F_U can be calculated based on CVT parameters such as gearbox fluid pressure and rotation speed (as described in the above-referenced WO2013/013915);
- F_z (wheel load for front and rear axle) can be determined by pressure sensors in the front axle and axle load sensors on the rear (as described in commonly-assigned International patent application WO2013/104981).
In the ONLINE Mode the operator enters the current ballasts attached. The system can determine the difference to ideal ballast accordingly. The operator can then be informed about:
- 1. Optimum tyre pressure for the current ballast
- 2. Optimum ballast
- 3. Optimum tyre pressure in combination with the optimum ballast (e.g. at 19,
FIG. 1 ).
A third embodiment of assistance system comprises the OFFLINE ballasting assistance in combination with an ONLINE tyre pressure assistance. In this case the rear wheel is not equipped with a wheel load sensor so that the OFFLINE ballasting assistance method is used to generate ballasting suggestions while alternative means such as an ultrasonic sensor is used at the rear to detect tyre pressure (by measuring distance between wheel rim bead and contact surface).
Although the above examples are given in terms of ballasting of a tractor front end and rear wheels, it will be readily understood that it may equally be applied to other weight distribution arrangements, for example with weighting on the rear linkage to counteract a front-linkage coupled implement. Other variations are possible and, as will be recognised, the method may be extended to incorporate a first range of a third operational parameter of the vehicle (for example engine load) and a second range, less than or equal to the first range, of discrete values of the third parameter to identify a three dimensional subset of derived ballasting option selections. As above, selection based on prevalence or probability within the subset is used to identify the recommended ballasting option.
In another variation, a full set of optimal ballast selections may be made across the range of vehicle operating (speed/weight) parameters. Having identified a fully populated version of the 3D table of
In a further variation, selection from the derived ballasting option selections may be made by a user following presentation of a graphic representation of the options. For example, when presented with a display equivalent to
For assisting selection by the user, the graphic representations shown in
In a still further variation, the driver may be presented with a menu enabling selection of a ballast variant, with the system then presenting further ballast variants, determined as above, for a predetermined range of values of e.g. working speed and/or vertical load. As an example, where the driver has selected a certain ballast configuration, the system will determine alternative ballast configurations and then present to the driver a graphic indicating the range of working speeds for which the selected ballasting is acceptable, too low, or too high.
In the foregoing we have described a method and system for selecting and indicating to a user one from a plurality of available ballasting options for an agricultural vehicle when coupled to an agricultural implement. The implement type defines operating ranges of discrete values for first, second and optionally third operational parameters of the vehicle, with the differing combinations defining a values subset. An optimal choice from the available ballasting options is made for each combination in the values subset, and a selection from the optimal choices based on prevalence or probability of occurrence is made and presented to the user. Operational parameters may include operating speed, loading due to implement weight and engine power.
Claims
1. A method for selecting and indicating to a user one from a plurality of ballasting options for an agricultural vehicle when coupled to an agricultural implement, comprising:
- within a first range of discrete values of a first operational parameter of the vehicle and a first range of discrete values of a second operational parameter of the vehicle, using a received identifier for a selected implement to look up a second range, less than or equal to the first range, of discrete values of the first parameter, and a second range, less than or equal to the first range, of discrete values of the second parameter to obtain a values subset from the combinations of discrete first and second operational parameter values;
- deriving a respective optimal selection from the plurality of ballasting options for each combination in the values subset;
- identifying one ballasting option selection on the basis of a predetermined selection criteria; and
- indicating the identified selection to the user.
2. The method as claimed in claim 1, wherein the predetermined selection criteria is prevalence of a particular one of the plurality of ballasting options within the values subset.
3. The method as claimed in claim 1, wherein the predetermined selection criteria is probability of occurrence of a particular one of the plurality of ballasting options within the values subset.
4. The method as claimed in claim 1, wherein the predetermined selection criteria is a user selection in response to a presented visual representation of the values subset.
5. The method as claimed in claim 1, wherein the first operational parameter of the vehicle is a working speed.
6. The method as claimed in claim 1, wherein the second operational parameter of the vehicle is a vertical load due to an implement on a connection between the said implement and the vehicle.
7. The method as claimed in claim 1, wherein the received identifier is obtained from a look-up table in response to user selection from a menu of implement types.
8. The method as claimed in claim 1, wherein each respective optimal selection from the plurality of ballasting options for each combination in the values subset is determined by:
- calculating of wheel load distribution (ceta) and total weight (mue) for each ballast option for each combination in the values subset;
- determining the differential current of wheel load distribution (ceta) and total weight (mue) compared to a predetermined optimum value for each ballast option for each combination in the values subset; and
- choosing as the respective optimal selection the ballast variant with the smallest sum of both differential currents.
9. The method as claimed in claim 1, further comprising identifying a first range of discrete values of a third operational parameter of the vehicle to extend the values subset to combinations of discrete first, second and third operational parameter values prior to the step of deriving an optimal selection.
10. A method as claimed in claim 9, wherein the third operational parameter of the vehicle is an engine loading.
11. The method as claimed in claim 1, further comprising storing an identified one ballasting option selection by reference to an identifier for the coupled agricultural implement.
12. A ballasting assistance system for an agricultural vehicle when coupled with an agricultural implement, the system comprising:
- a display device;
- a data storage device; and
- a data processing device in communication with the display device and the data storage device, the data processing device configured to select one from a plurality of stored ballasting options for the agricultural vehicle when coupled to a selected agricultural implement, by performing the steps of: within a first range of discrete values of a first operational parameter of the vehicle and a first range of discrete values of a second operational parameter of the vehicle, using a received identifier for the selected implement to look up in the data storage device a second range, less than or equal to the first range, of discrete values of the first parameter, and a second range, less than or equal to the first range, of discrete values of the second parameter to obtain a values subset from the combinations of discrete first and second operational parameter values; deriving a respective optimal selection from the plurality of ballasting options for each combination in the values subset; identifying one ballasting option selection on the basis of a predetermined selection criteria; and displaying the identified one ballasting option selection on the display device.
13. A ballasting assistance system as claimed in claim 12, wherein the display device is a touch screen device and the received identifier is obtained from a look-up table in the data storage device in response to user selection via the touch screen from a menu of implement types displayed.
14. A ballasting assistance system as claimed in claim 12, further comprising wireless communication means, and the received identifier is obtained from a remotely stored look-up table in response to user selection via the data processing device.
15. A data storage device carrying data defining a software utility, said software utility when loaded to a data processing device in communication with a display device providing a ballasting assistance system for an agricultural vehicle coupled with an agricultural implement in which ballasting assistance system the data processing device is configured to select one from a plurality of stored ballasting options for the agricultural vehicle when coupled to the agricultural implement, by performing the steps of:
- within a first range of discrete values of a first operational parameter of the vehicle and a first range of discrete values of a second operational parameter of the vehicle, using a received identifier for the selected implement to look up in the data storage device a second range, less than or equal to the first range, of discrete values of the first parameter, and a second range, less than or equal to the first range, of discrete values of the second parameter to obtain a values subset from the combinations of discrete first and second operational parameter values;
- deriving a respective optimal selection from the plurality of ballasting options for each combination in the values subset;
- identifying one ballasting option selection on the basis of a predetermined selection criteria; and
- displaying the identified one ballasting option selection on the display device.
Type: Application
Filed: Aug 13, 2015
Publication Date: Oct 12, 2017
Inventors: Thiemo Buchner (Saal a.d. Donau), Benno PICHLMAIER (Muenchen)
Application Number: 15/514,143